I’m a horrible person

My boyfriend and I have been together for 8 years and we have two kids together. I’ve always been the affectionate type but after a couple of years I noticed I wasn’t getting that affection back, so I started not showing any affection. For years I felt so insecure about myself because he would never want to be intimate or give me any attention. It’s like I had to beg him to love me. He does everything for my kids and I, he does laundry most of the time and if I ask for something to be done around the house he will do it, on his own time but it gets done (most times.) he pays all the bills, I buy our children mostly everything and I pay my car other than that he pays everything else. So anyway, i met this guy at work and he makes me happy. .i tell myself this can’t be but i really cant help it he asked for my number so I gave it to him, he texts me good morning every morning, good night nothing bad but ever since I met him ive kind of been pushing off my boyfriend and I think he feels it because he wants to be affectionate now and actually wants to cuddle and watch tv together but now I don’t want to. Idk what to do? I haven’t been happy in this relationship for a while but change is so scary. Advice plllleeeaase